Cosmo 101

Ok so hop back into your glass elevator we’re gonna need it again. So let’s get some more goobstopers and do a little experiment. The experiment is to toss one lightly up into the air and see what happens. First let’s start out on earth. You’re just sitting there in the chocolate factory and you throw the goobstoper up into the air. What does it do? It goes up and slows down, then comes to a stop and falls back down. Ok after you record the results you take off into space and find a nice little spot away from any gravitational fields. You cut the power and drift along at a nice constant velocity. Now you try the experiment again. You throw the goobstoper up but this time it just keeps going until it hits the ceiling. Hmm…interesting. Now you turn your power back on and set the controls to accelerate you at 9.8 meters per second per second (the ‘acceleration of gravity’ felt on earth) and you do the experiment again. This time the goobstoper goes up and comes back now just the way it would on earth. Very peculiar. Well now you go back towards earth and let yourself free fall down towards the earth. Now we repeat the experiment one more time. This time when you throw the goobstoper up it keeps going just as it did when you at constant velocity in deep space. This set of thought experiments is called the Equivalence Principle and, more succinctly, look like this:

A lab on earth = an accelerating lab in deep space

And a non-accelerating lab in deep space = a feel-fall lab on/near earth

Now there is one distinction that must be made. When I say earth what I really mean is a uniform gravitational field (remember the experiment from last night), but on earth’s surface it’s very close to uniform. You know what, I think I’ve been spelling goobstoper wrong…by George I have! It’s spelled gobstopper. Oh well, you knew what I meant.